Numerous machines have been developed for the application of paper labels to formed articles such as bottles, cans, cups and the like. The articles so labeled are usually rigid and have a smooth, hard and generally cylindrical surface. The labeling art for such containers has been highly developed and high quality labels can be applied to the containers at high speeds using various adhesives.
The labeling of containers that are not inherently rigid and strong presents a more difficult labeling problem. For example, the decoration of foamed polystyrene cups, which are finding increasing use as disposable cups for holding both hot and cold liquids, is difficult because of the rough surface characteristics and the softness of the cup material. The use of labels on such cups is particularly desirable, since, in addition to the decoration provided by the label, a thin paper label adhered to a thin walled polystyrene cup provides a cup structure in which the rigidity of the cup is increased dramatically over that of an unlabeled cup of similar wall thickness. However, known labeling machines are not well adapted to apply relatively thin labels (1 to 2 mils in thickness) to containers in general; nor are they adapted to apply such labels in particular to soft, rough surfaced containers such as foamed plastic cups.
Disposable cups are typically formed in the shape of a frustum of a cone, rather than a cylinder, to allow the cups to be nestably stacked for delivery. Labels to be applied to cups having a conical surface, when flat, will have the shape of a sector of an annulus, rather than being rectangular as a label applied to a cylinder would be. The shape of the label complicates the problems of handling the label, delivering it to the cup, precisely positioning it and adhering it to the surface of the cup.